Bellwork 3/22/12 Define: Elevation, Flow Rate, Fluid, Fluid Dynamics, Force, Hydrodynamics, Pressure Evaluating Energy Resources Renewable
Future availability Net energy yield It takes energy to get energy
Habitat degradation Cost (initial and ongoing) Community disruption Political or international issues
Suitability in different locations Polluting (air, water, noise, visual) Important Nonrenewable Energy Sources Fossil Fuels What are the fossil fuels?
FOSSIL FUELS 85% of the worlds commercial energy COAL NATURAL GAS
OIL 20 richest countries consume: 50% of coal 80% of natural gas 65% of oil North American Energy Resources
US has only 2.4% of worlds oil reserves Average American uses in one day what a person in the poorest countries use in one year
COAL Fossilized, condensed carbon-rich fuel 10 X reserves of oil/gas, last 200 years at present rate Coal What is it?
Solid fossil fuel formed in several stages Land plants that lived 300-400 million years ago Subjected to intense heat and pressure over many millions of years Mostly carbon, small amounts of sulfur Coal Formation and Types
Coal what do we use it for? Stages of coal formation 300 million year old forests peat > lignite > bituminous > anthracite Primarily strip-mined Used mostly for generating electricity Used to generate 62% of the worlds electricity
Used to generate 52% of the U.S. electricity Enough coal for about 200-1000 years U.S. has 25% of worlds reserves High environmental impact Coal gasification and liquefaction
Coal: Trade-offs Worlds most abundant fossil fuel Mining and burning coal has a severe environmental impact Accounts for over 1/3 of the worlds CO2 emissions Discussion Questions?
How is your classroom lit? Where does the electricity come from to power the lightbulbs in your classroom? How much do you think it costs to light your classroom for one hour? Calculating Costs The electricity needed for the fluorescent
tubes used to light most classrooms costs approximately three-tenths of a cent per hour. Can you figure out how much it would cost to light our classroom for 1 hour? N x 0.003 = Cost/hour How much would it cost for the entire day? Week? Year?
Coal Costs It takes approximately 1 ton of coal to produce 2,500 kilowatthours (kWh) of electricity (or 1 pound of coal to produce 1.25 kilowatt-hours) The average fluorescent tube uses 18 watts per hour or .018 kilowatt-hours of power per bulb. How much coal do we use in 1 hour to light the school? 1 week? 1 year?
